Summary

Isolated acetabular decompression may adequately address the underlying impingement in combined-type FAI while avoiding the risks associated with femoral-sided decompression.

Abstract

Background

The cam and pincer type lesions of femoroacetabular impingement cause repetitive damage to the chondrolabral junction and acetabular labrum. While each lesion is typically separately addressed, femoral osteochondroplasty carries a risk of avascular necrosis, heterotopic ossification, and femoral neck fracture.

Hypothesis

Volumetric acetabular rim resection and labral repair alone may allow for adequate decompression and earlier weight bearing in combined-type FAI.

Study Design: Case series; Level of evidence, IV.

Methods

A review of a prospectively collected registry identified 86 patients (106 hips) with an average age of 38.1 years (range, 17-59 years) with combined-type FAI that underwent isolated acetabular osteoplasty and labral repair. Preoperative a-angle, degree of radiographic degenerative changes, and presence of a crossover sign were recorded. Clinical outcomes were assessed with the modified Harris Hip Score (MHHS), international hip outcome score (iHOT-12), sports specific hip outcome score (HOS-SSS), and patient satisfaction score (out of 10) at a minimum two-year follow-up.

Results

Clinical follow-up was obtained at a mean follow-up of 37.2 months (range, 27.9-79.2 months). Patients with Tönnis grade 0 and I findings had significantly higher mHHS (83.5 vs. 71.5, p = 0.01), HOS-SSS (81.3 vs. 59.9, p = 0.02), and iHOT-12 scores (71.1 vs. 58.8, p = 0.04) compared to patients with Tonnis grade II changes. However, patient satisfaction scores (8.0 vs. 7.2, p = 0.45) were no different. No significant difference was noted between unilateral and bilateral hip patient outcome scores. Patient age and preoperative alpha angles did not correlate with any outcome scores (all r2 <0.05). There were no cases of revision surgery or progression to arthroplasty.

Conclusion

Isolated acetabular decompression may adequately address the underlying impingement in combined-type FAI while avoiding the risks associated with femoral-sided decompression. Comparable to studies using combined decompression techniques; good-to-excellent patient reported outcomes and satisfaction scores were noted with significantly higher scores in patients with minimal arthritic change. Patient age and preoperative a-angle had less effect on postoperative outcomes.

Key Terms: femoroacetabular impingement; hip arthroscopy; acetabular labrum; acetabular osteoplasty